We naturally tend to talk offense first when it comes to evaluating position players.

That shouldn’t be the case with catchers. Defense should always be the first order of business.

That’s why the Cubs’ signing of Dioner Navarro hasn’t been a headline grabber–he’s no Buster Posey at the plate. But that doesn’t diminish the importance of the signing or the fact Navarro can upgrade the Cubs defensively.

The catching position has been an area of weakness on the Cubs for several years now. Geovany Soto steadily declined from his Rookie of the Year Award season in 2008 and all else can be summed up with two words: Koyie Hill.

That’s actually a critical fault when you consider catcher is not only the toughest position to play, but arguably the most important position on the diamond.

From learning to handle an entire pitching staff, to working the individual game-plans, to controlling the running game and all the way down to simply framing pitches, it’s a crucial part of a winning team. If a catcher can hit some, all the better. But it’s what he does behind the plate that truly counts.

It would be wonderful if Welington Castillo reaches the potential the Cubs’ organization believes he can. Epstein has tabbed Castillo a potential core-player in the rebuild. Dale Sveum envisions him as a future Gold Glove Award winner.

Obviously, we hope both projections turn out to be true. But what if Epstein and Sveum (and myself included) are all wrong about Welington? What happens if he succumbs to a sophomore slump like Soto did in 2009, or worse, suffers another injury like he did last season (sprained right knee)? Then who will the Cubs turn to?

Until the arrival of Navarro, that would’ve been Steve Clevenger, still an unproven and inexperienced catcher–both at the plate and behind it. Navarro, however, has caught 600-plus games in the big leagues (including 3 seasons catching Matt Garza), was the starting catcher for the pennant winning Rays in ’08 and even earned an All Star nod the same season.

There’s a reason Navarro’s managed to have an 8-year big-league career despite being a career .245/.306/.357 hitter; he can do everything needed behind the plate of a back-up, big-league catcher.

So before being critical of Navarro’s lack of offensive production or the Cubs’ willingness to pay him $1.75-million, it’s worth reminding ourselves how important upgrading the catching position was given Castillo and Clevenger are still unproven.

Spending less than $2-million to ensure there’s a solid Plan B at the most important position on the field wouldn’t appear a poor investment.

Navarro isn’t that prominent ‘headline’ signing Cubs fans are waiting for this winter, but he could turn out to be one of the more important signings the Cubs make this offseason—even if he doesn’t hit a lick.

Hot-hitting Steve Clevenger, off to a 11-for-22 start at the plate, was on the brink of becoming Dale Sveum’s everyday catcher before suffering tightness in his right side.

The injury forced Clevenger to the 15-day DL on April 30, which doesn’t expire until next Tuesday.

But even from the training table Clevenger appears to have the upper hand on Geovany Soto, whose season-long slump has dropped his batting average to .152, ranking 29th among major league back stoppers.